DE102017202359A1 - ENERGY STORAGE MODULE, ENERGY STORAGE SYSTEM, VEHICLE AND METHOD FOR MEASURING A CELL VOLTAGE - Google Patents

Abstract

The invention relates to an energy storage module, in particular a solid-state battery, an energy storage system, a vehicle and a method for measuring an electrical voltage on such an energy storage module or such an energy storage system. Two energy storage cells arranged in a stack and connected in series each have an anode layer and a cathode layer. A contact element, which is electrically connected to an anode layer of a first energy storage cell lying in the interior of the stack and to a second energy storage cell located in the interior of the stack of a second energy storage cell adjacent to the first energy storage cell, is led out of the stack such that the at least one contact element extends from outside the Stack is electrically contacted.

Description

The invention relates to an energy storage module, in particular a solid-state battery, for the electrochemical storage of energy, an energy storage system with such energy storage modules, a vehicle having such an energy storage module or energy storage system and a method for measuring an electrical voltage to such an energy storage module or energy storage system.

Solid-state batteries are electrochemical energy storage cells in which solid-state electrolytes are used instead of liquid electrolytes. Through the use of solid electrolyte significantly higher energy densities are achieved than with liquid electrolytes. Furthermore, this simplifies the production of such cells and increases their safety during operation. In order to increase the achievable voltages, several energy storage cells are usually connected in series.

It is an object of the invention to enable a further increase in the reliability of an energy storage module during operation and in particular to achieve a longer service life with high energy density.

This object is achieved by an energy storage module, an energy storage system, a vehicle and a method for measuring an electrical voltage on such an energy storage module and / or energy storage system according to claims 1, 8, 9 and 10, respectively.

An inventive energy storage module, in particular in the form of a solid state battery, for the electrochemical storage of energy has at least two arranged in a stack and connected in series energy storage cells, each having an anode layer and a cathode layer, and is characterized by at least one contact element, which with a in Inside the stack lying anode layer of a first energy storage cell and electrically connected to a lying in the interior of the stack cathode layer of the first energy storage cell second energy storage cell and is led out of the stack, so that the at least one contact element from outside the stack is electrically contacted.

An inventive energy storage system has at least two energy storage modules according to the invention, wherein the energy storage modules are arranged side by side and / or one above the other, that touch at least one led out of a first energy storage module contact element and at least one out of a first energy storage module adjacent second energy storage module led out contact element.

A vehicle according to the invention, in particular a motor vehicle, has an energy storage module according to the invention and / or an energy storage system according to the invention. The vehicle preferably has an electric drive or hybrid drive.

An inventive method for measuring an electrical voltage to an energy storage module according to the invention and / or energy storage system having at least two contact elements, between which one or more energy storage cells are arranged, is characterized in that an electrical voltage to each two contact elements, which consists of a stack of connected in series energy storage cells are led out, tapped and measured.

One aspect of the invention is based on the approach that the electrochemical energy storage cells form a so-called. Bipolar stack in which the anode and cathode layer of adjacent energy storage cells are electrically connected by an electrically conductive contact element, wherein the contact element is led out of the stack to to access it outside the stack. As a result, the particular potential, in particular the individual cell voltage (also referred to below as "single-cell voltage"), of the individual cells connected in series can be easily tapped and measured in order to obtain information about the individual state of charge of the individual energy storage cells, for example.

As a result of the measurement or monitoring of the individual cell voltages of the cells connected in series in the bipolar stack, an imminent overcharge and / or total discharge of the individual cells during charging or discharging of the energy storage module can be recorded in time to avoid the damage of individual cells Initiate countermeasures in good time. For example, if necessary, e.g. in an impending overcharge or exhaustive discharge of individual cells, the state of charge of individual energy storage cells are influenced by externally via the contact elements or discharged charges, such as by an electrical power source or an electrical load to two contact elements, in particular one with the cathode and one with the anode of a single cell connected contact element, is created or connected.

Overall, the invention enables a further increase in the reliability of an energy storage module during operation. As a result, longer lifetimes can be achieved with high energy density.

In a preferred embodiment, the at least one contact element has an electrically conductive contact layer, which runs essentially parallel to the respective anode layer and cathode layer and is electrically connected to the anode layer and the cathode layer. In this case, the contact layer forms an electrically conductive intermediate wall or layer arranged between adjacent cells, by means of which the anode and cathode layers of the adjacent cells are connected to one another. The contact layer, which may also be referred to as a bipolar plate or as a current collecting layer, preferably extends over the entire cross section of the stack. Thus, the surface of the contact layer forms the conductor cross section for the operating current, which flows in the stacking direction. Preferably, the at least one contact element is led out of the stack on a side surface of the stack, in order to allow a contact from the outside in a particularly simple manner. In this case, the side surface of the stack runs essentially parallel to a stacking direction, in which the energy storage cells, in particular the anode and cathode layer, are stacked in stack stacking or juxtaposed, and / or perpendicular to the anode and cathode layers.

In a preferred embodiment, the at least one contact element has a contact surface extending substantially parallel along the side surface of the stack, which contact surface is electrically contactable from outside the stack. About such a contact surface, the at least one contact element can be contacted particularly reliable.

Preferably, the contact surface is spaced from the side surface of the stack, for example by a contact lug of the contact element which is laterally, i. perpendicular to the stacking direction, protruding from the stack. Alternatively or additionally, the contact surface with respect to the side surface, in particular with respect to one or more anodes or cathode layers, of the stack is electrically insulated. In both cases, a short circuit is easily avoided.

In a further preferred embodiment, the contact surface along the side surface of the stack, in particular in the stacking direction and / or perpendicular to the contact layer, an extent which is greater than the thickness of the contact layer. The contact surface preferably extends along the side surface of the stack, in particular in the stacking direction, over more than 100 μm, preferably more than 250 μm, particularly preferably more than 500 μm. This reduces the risk of a faulty contact, in particular the contacting of an anode or cathode layer or the generation of an electrical short circuit.

In a further preferred embodiment, the contact surface is adapted to enter into a plug connection with a contact surface of another energy storage module and / or an electrical line. Preferably, the contact surface for this purpose has a first plug-in or latching element, which can be connected to a corresponding second plug-in or latching element of a contact surface of another energy storage module and / or an electrical line such that an electrical connection is made. This allows electrical interconnection with other energy storage modules in a fast, easy and reliable manner.

In a further preferred embodiment, a plurality of contact elements are led out of the side surface of the stack, each having a contact surface, wherein the respective contact surfaces are arranged offset in two dimensions of the side surface, so that different contact surfaces not only in the stacking direction, but also perpendicular to the stacking direction different positions to have. Preferably, the offset of two adjacent contact surfaces perpendicular to the stacking direction is greater than the extension of the contact surfaces perpendicular to the stacking direction. By the offset perpendicular to the stacking arrangement, the expansion of the individual contact surfaces in the stacking direction can be chosen sufficiently large to - to allow a safe and easy electrical contact without the risk of contact or overlap with an adjacent contact surface.

In a further preferred embodiment, the contact surfaces of the contact elements are arranged substantially along a diagonal of the side surface of the stack. Thereby, a regular arrangement of the contact surfaces is achieved, in particular at the maximum possible distance of the contact surfaces perpendicular to the stacking direction. This makes the contacting particularly safe and easy. If you also put two such energy storage modules together with their side surfaces to each other, then the respective contact surfaces of the energy storage modules come into contact, and these can be interconnected in a simple and reliable way to an energy storage system.

In a further preferred embodiment of the method for measuring an electrical voltage on an energy storage module and / or an energy storage system, the electrical Tension at each two contact elements, which are each connected to the anode layer and the cathode layer of an energy storage cell and led out of the stack, tapped and measured. As a result, the cell voltage of a single energy storage cell can be detected reliably in a stack with a plurality of energy storage cells and, as a result, the operating state, in particular charge state, of the individual energy storage cell can be determined. Alternatively, an electrical voltage of a plurality of energy storage cells in a plurality of stacks, which are connected in parallel in an energy storage system, can thereby also be detected, without it being necessary to measure several individual energy storage cells.

• 1 ein erstes Beispiel eines Energiespeichermoduls;
• 2 ein zweites Beispiel eines Energiespeichermoduls; und
• 3 ein Beispiel zur Verschaltung von Energiespeichermodulen zu einem Energiespeichersystem.

Other features, advantages and applications of the invention will become apparent from the following description taken in conjunction with the figures. Show it:

• 1 a first example of an energy storage module;
• 2 a second example of an energy storage module; and
• 3 an example of the interconnection of energy storage modules to an energy storage system.

1 shows a first example of an energy storage module 1 with three in the stacking direction 3 stacked energy storage cells 4 , Each of the energy storage cells 4 has an anode layer formed, for example, as a thin film 5 and a cathode layer 6 on, between each of which a solid electrolyte 7 located. The anode layers 5 are preferably formed as lithium anodes. The cathode layers 6 are preferably formed as composite cathodes.

The energy storage cells connected in series in this way 4 form a so-called bipolar stack 2 ,

Furthermore, electrically conductive contact elements 8th provided, which are formed as contact layers and in each case between an anode and cathode layer 5 . 6 of two adjacent energy storage cells 4 are arranged and electrically connected to these. The contact elements 8th are preferably formed as thin layers whose layer thickness in the stacking direction 3 preferably less than 100 microns. Due to the electrically conductive connection to the respective anode and cathode layers 5 . 6 are the contact elements 8th on the electrical potential of the respective anode or cathode layer 5 . 6 ,

The contact elements 8th are out of the pile 2 brought out and set up, from outside the pile 2 to be contacted, in particular to the electrical voltage of a single energy storage cell 4 on two contact elements 8th , which at the cathode layer 6 (in the example in stacking direction 3 above) and anode layer 5 (in the example in stacking direction 3 below) of the energy storage cell 4 abut, measure and measure. This makes it possible, despite series connection in the form of a bipolar stack 2 the voltages of the individual energy storage cells 4 if necessary - for example, in case of impending over-discharge or over-charging of a single cell 4 - be able to take the necessary countermeasures in time.

On the other hand, the measurement of the total stress of the stack would be 2 by contacting the uppermost cathode layer 6 and the bottom anode layer 5 of the pile 2 in view of imminent damage to a single cell 4 significantly less meaningful, causing damage to the individual cell 4 - and as a consequence of the entire module 1 - could not be reliably avoided.

2 shows a section of a second example of an energy storage module, wherein the contact elements 8th each with a contact surface 10 are provided, which are substantially parallel to a side surface 9 of the pile 2 or perpendicular to the anode and cathode layers of the stack 2 extends. About the contact surfaces 10 can be located between the individual cells contact layers of the contact elements 8th be contacted particularly reliably and safely from the outside.

The contact surfaces 10 are plate-shaped in the example shown and have a thickness which is preferably approximately the thickness of the contact layer of the contact elements 8th equivalent. Alternatively, the thickness of the contact surfaces 10 but also larger than the layer thickness of the contact elements 8th be chosen to increase the mechanical stability of the contact surfaces 10 continue to increase.

The contact surfaces 10 point in the stacking direction 3 an extent which is greater than the thickness of the contact layer of the contact elements 8th so that the contact surfaces 10 in the stacking direction 3 over the respective contact layer of the contact elements 8th protrude and, as exemplified, a portion of each adjacent energy storage cells 4 in the area of the side surface 9 of the pile 2 overtop.

In the example shown, the extent of the contact surfaces 10 in the stacking direction 3 slightly larger than the extent of the energy storage cells 4 in the stacking direction 3 so that the contact surfaces 10 each to about the middle of the adjacent energy storage cell 4 protrude. The lower edge 10 'of an upper contact surface 10 then lies approximately at the height of the upper edge 10 "of an adjacent lower contact surface 10 ,

Basically, the extent of the contact surfaces 10 in the stacking direction 3 but significantly larger, for example, about twice as large, be as or as the extent of the energy storage cells 4 in the stacking direction 3 , The lower edge 10 'of an upper contact surface 10 would then be below the top edge 10 "of an adjacent bottom contact surface 10 lie (not shown).

To overlap or an electrical contacting of two adjacent contact surfaces 10 To easily and reliably avoid, are the contact surfaces 10 as shown in the example, preferably perpendicular to the stacking direction 3 staggered.

Due to the described dimensioning of the contact surfaces 10 On the one hand and the staggered arrangement on the other hand, a simple and reliable contacting of the contact surfaces 10 allows, without the risk of short circuits of the contact surfaces 10 to increase among themselves.

The contact elements 8th In the example shown furthermore each have a conductor lug 11 on, through which the contact elements 8th on the side surface 9 from the pile 2 leads out and each with a contact surface 10 get connected. Through the conductor flags 11 will ensure that the contact surfaces 10 at a predetermined distance from the side surface 9 of the pile 2 are spaced so that a short circuit between elements of the energy storage cells 4 and / or adjacent energy storage cells 4 is prevented.

Even if the contact surfaces 10 in the example shown only on one side surface 9 of the pile 2 are attached, it is possible or may be advantageous, this at two or more side surfaces of the stack 2 to be mounted in order to allow an electrical contact from the outside, in particular by contact surfaces of one or more other stacks (not shown). For example, for the purpose of parallel connection of a plurality of stacks constructed in the same way 2 the contact surfaces 10 on both opposite side surfaces 9 of the respective stack 2 be provided. This will be described below with reference to FIG 3 explained in more detail. 3 shows an example of the interconnection of energy storage modules 1 , In the example shown, two energy storage modules adjoining each other with their respective side surfaces 1 connected in parallel and form an energy storage system 12 ,

As with an additional energy storage module 1 Illustrated are the energy storage modules 1 configured and / or arranged so that the perpendicular to the stacking direction 3 staggered contact surfaces 10 on the side surfaces of adjacent energy storage modules 1 lie opposite each other and when joining the energy storage modules 1 , indicated by the arrow 13 to be brought into electrical contact with each other.

This results in a charge balance between two or more adjacent energy storage cells 4 (please refer 1 and 2 ) of different energy storage modules 1 allows, since the electrodes of energy storage cells of the energy storage system 12 over the contact surfaces 10 or contact elements 8th (please refer 1 and 2 ) are conductively connected such that they each have an effective electrode of the energy storage system 12 form.

The electrical cell voltage of all perpendicular to the stacking direction 3 in a plane adjacent energy storage cells is the same and can easily over two in the stacking direction 3 adjacent contact surfaces 10 laterally, ie perpendicular to the stacking direction 3 , from the energy storage system 12 be led out and measured. The effort to monitor, for example, the state of charge of the energy storage cells or the energy storage system 12 is therefore independent of the number of parallel energy storage modules 1 ,

LIST OF REFERENCE NUMBERS

1

Energy storage module

2

stack

3

stacking direction

4

Energy storage cell

5

anode layer

6

cathode layer

7

Solid electrolyte

8th

contact element

9

side surface

10

contact area

11

conductor tab

12

Energy storage system

13

Arrow (assembling the energy storage modules)

Claims (11)

Energy storage module (1), in particular solid state battery, for electrochemical storage of energy with at least two in a stack (2) arranged and connected in series energy storage cells (4), each having an anode layer (5) and a cathode layer (6), characterized by at least a contact element (8) which is adjacent to an anode layer (5) of a first energy storage cell (4) lying inside the stack (2) and to a cathode layer (6) of one of the first energy storage cell (4) lying in the interior of the stack (2) second energy storage cell (4) is electrically connected and led out of the stack (2), so that the at least one contact element (8) from outside the stack (2) is electrically contacted. Energy storage module (1) after Claim 1 wherein the at least one contact element (8) has a contact layer which is substantially parallel to the respective anode layer (5) and cathode layer (6) and is electrically connected to the anode layer (5) and the cathode layer (6). Energy storage module (1) after Claim 1 or 2 in that the at least one contact element (8) has a contact surface (10) extending substantially parallel along a side surface (9) of the stack (2) and which is electrically contactable from outside the stack (2). Energy storage module (1) after Claim 2 and 3 wherein the contact surface (10) along the side surface (9) of the stack (2), in particular perpendicular to the contact layer, has an extension which is greater than the thickness of the contact layer. Energy storage module (1) according to one of Claims 3 or 4 , wherein the contact surface (10) is adapted to enter into a plug connection with a contact surface (10) of another energy storage module (1) and / or an electrical line. Energy storage module (1) according to one of Claims 3 to 5 wherein a plurality of contact elements (8) are led out of the side surface (9) of the stack (2) and the respective contact surfaces (10) are offset in two dimensions of the side surface (9). Energy storage module (1) after Claim 6 wherein the contact surfaces (10) of the contact elements (8) are arranged substantially along a diagonal of the side surface (9) of the stack (2). Energy storage system (12) with at least two energy storage modules (1) according to one of the preceding claims, wherein the energy storage modules (1) are arranged side by side and / or one above the other, that at least one of a first energy storage module (1) led out contact element (8) and at least touching a contact element (8) led out of a second energy storage module (1) adjacent to the first energy storage module (1). Vehicle, in particular motor vehicle, with an energy storage module (1) according to one of Claims 1 to 7 and / or an energy storage system (12) Claim 8 , Method for measuring an electrical voltage on an energy storage module (1) according to one of Claims 1 to 7 and / or an energy storage system (12) Claim 8 , with at least two contact elements (8) between which one or more energy storage cells (4) are arranged, characterized in that an electrical voltage is applied to two contact elements (8) led out of a stack (2) of energy storage cells (4) connected in series. tapped and measured. Method according to Claim 10 , wherein the electrical voltage at each two contact elements (8), which are respectively connected to the anode layer (5) and the cathode layer (5) of an energy storage cell (4) and led out of the stack (2), tapped and measured.

Images